我想更改条形图中所选条形的颜色，我发现了此代码，但当我运行此代码时，显示了此错误myChart.getElementsAtEvent不是HTMLCanvasElement.ChangeColor中的函数
这是我代码
HTML格式：

           <div class="chartBox">
              <canvas id="myChart"></canvas>
              <input type="color" id ="colorPicker" hidden/>                      
            </div>
```

Javascript程式码：

<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>

        <script type="">
            var color = '#456212';
            var lastIndex = null;
            var canvas = document.getElementById("myChart");

          document.getElementById("my-select").addEventListener("change", changeChart);
          document.getElementById("filter").addEventListener("change", filterChart);

          var label = <%- JSON.stringify(x)%>
          var data = [<%= y %>]
          const originalLabels = label;
          const originalData = data ;

          var ctx = document.getElementById('myChart').getContext('2d');
          var myChart = new Chart(ctx, {
            type: 'bar',
            data: {
              labels: originalLabels,
              datasets: [{
                label: '# of Votes',
                data: originalData,
                backgroundColor: [
                  'rgba(255, 99, 132, 0.2)',
                  'rgba(54, 162, 235, 0.2)',
                  'rgba(255, 206, 86, 0.2)',
                  'rgba(75, 192, 192, 0.2)',
                  'rgba(153, 102, 255, 0.2)',
                  'rgba(255, 159, 64, 0.2)'
                ],
                borderColor: [
                  'rgba(255, 99, 132, 1)',
                  'rgba(54, 162, 235, 1)',
                  'rgba(255, 206, 86, 1)',
                  'rgba(75, 192, 192, 1)',
                  'rgba(153, 102, 255, 1)',
                  'rgba(255, 159, 64, 1)'
                ],
                borderWidth: 1
              }]
            },
            options: {
              scales: {
                y: {
                  beginAtZero: true
                }
              }
            }
          });
canvas.addEventListener("click", ChangeColor, false);

     colorPicker = document.getElementById('colorPicker');

     colorPicker.addEventListener("change", getColor, false);

    function getColor(e){

       //
        console.log(this.lastIndex)
        myChart.data.datasets[0].backgroundColor[lastIndex] =  e.target.value;
        console.log(e.target.value);
        myChart.update();

    }

 function ChangeColor(e){
        e.preventDefault();
        var activePoints = myChart.getElementsAtEvent(e);
        lastIndex = activePoints[0]._index;
        this.color = myChart.data.datasets[0].backgroundColor[lastIndex];
        console.log('Before', this.color);
        var colorPicker = document.getElementById('colorPicker').click();
        //console.log('After',this.color);
    }

</script>

我如何改变一个特定的酒吧颜色
我希望用户点击栏，然后选择颜色或相反